<h2>DESCRIPTION</h2>

Module <em>r3.gradient</em> computes gradient from a 3D raster map. 
Results are three 3D raster maps describing the x, y, z components of 
the computed gradient field.

<h2>EXAMPLES</h2>

<div class="code"><pre>
# create a 3D raster
g.region s=0 n=100 w=0 e=100 b=0 t=100 -p
r3.mapcalc "test_gradient = sqrt(row()*row() +col()*col()+ depth()*depth())"

# compute gradient
r3.gradient input=test_gradient output=grad_x,grad_y,grad_z
</pre></div>

<h2>SEE ALSO</h2>

<em>
<a href="r3.flow.html">r3.flow</a>,
<a href="r.flow.html">r.flow</a>
</em>

<h2>AUTHORS</h2>

Anna Petrasova, <a href="http://geospatial.ncsu.edu/osgeorel/">NCSU OSGeoREL</a>,
developed during GSoC 2014.

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